1. Field of the Invention
Implementations described herein relate generally to network communications and, more particularly, to processing multicast traffic.
2. Description of Related Art
Conventional network devices, such as routers, transfer packets through a network from a source to a destination. Typically, the router performs a lookup using information in the header of the packet, identifies a destination and forwards the packet to the destination. In some cases, an incoming data packet is forwarded to a number of destinations. For example, the data packet may be a multicast packet intended for a number of different destinations.
In this case, the router must replicate the data packet and forward copies of the replicated data packet to a number of output devices or interfaces associated with the multiple destinations. One problem associated with multicast traffic is that the data replication is time consuming and takes considerable processing resources. For example, in conventional systems, a single ingress forwarding device may need to replicate each packet a large number of times, such as four or more, to forward the data packet to the appropriate output devices/interfaces. Another problem occurs in cases where the single ingress forwarding device interfaces with a switch fabric to forward the replicated packets to the output forwarding devices/interfaces. In these cases, the bandwidth to the switch fabric may be limited. Therefore, conventional systems for processing multicast data may significantly slow data throughput on the router and increase congestion on the router. In addition, in some cases, the router must drop packets in order to maintain the desired line rate and avoid other congestion related problems.